38 WILLIAM G. DIETZ, M. D. 



Hab. — Colorado (Durango). 



Two female specimens in my collection. A very distinct and 

 easily recognized species. 



I. tenescens Wish. — Dyar's List, p. 569, No. 6478. — "Antennae whitish at 

 base, tending to piceous beyond. Palpi whitish. Head yellowish white. Thorax, 

 forewings and cilia unicolorous, pale, golden brown. Hind wings purplish gray: 

 cilia gray. Abdomen grayish. Lateral claspers elongate, triangular, upturned, 

 deeply excised beneath near the base and with an inwardly projecting short 

 point at their lower extremity; uncus short, obtuse, projected but not hooked." 



Exp. % , 14.0 mm. ; ? , 12.0-13.0 mm. 



Hab. — Oregon (Rogue River). U. S. Nat. Mus. collection. I 

 have not seen this species. 



I. politella Wish.— Dyar's List, p. 569, No. 6482.— Head, palpi, thorax and 

 wings a pale yellowish white, with a faint grayish tint, particularly at base of 

 costa and along veins. Last joint of labial palpi flattened. Scales of head some- 

 what appressed. An tenure slender, dark fuscous, about two-fifths the length of 

 forewings, joints longer than wide, feebly unipectinated in the male. Forewings 

 elongate-oval. Hindwings more grayish. Abdomen and legs grayish fuscous. 

 Cilia concolorous. 



Exp. 14.0-17.0 mm. ; 0.56-0.68 inch. 



Hab. — Oregon (The Dalles and Rogue Rivers) ; Colorado (S. 

 Park ; Chimney Gulch). 



Three specimens, 2 males, 1 female, from Colorado and determined 

 by Lord Walsingham, do not show the aeneous tinge mentioned by 

 his Lordship in the description of the species. The labial palpi, 

 which are rather long, are strongly ascending in one specimen, and 

 with the third joint slightly drooping in the other two. 



GROUP III. 



The two species of this group, I refer with grave doubts to the 

 genus under consideration, they are small, scarcely exceeding one- 

 quarter inch in expanse. Forewings ovate-lanceolate, fuscous brown, 

 with seneous lustre and pale fascia and marginal spots ; hindwings 

 ovate-lanceolate, pointed, with hair-like scales, and are distinguished 

 as follows : 



Head fuscous brown ; no spot in apical part of forewing labrariorel la. 



Head sordid white; a pale spot in apical part of wing aureovirens. 



I. labradurella Clem. — Dyar's List, p. 569, No. 6480. — "Forewings fus- 

 cous, with a brassy hue, with a white band at the basal third of the wing and an 

 opposite dorsal and costal spot of the same hue at the apical third of the wing 

 and which nearly meet in the middle of the wing. Cilia concolorous with fore- 



